Variable speed feed mechanism



NOV. 10, 1953 l 1 G, MC|| VA|N, JR 2,658,406

VARIABLE SPEED FEED MECHANISM Filed May 4, 1951 2 Sheets-Sheet l kdmNOV. 10, 1953 J, G MolLVAlN, j 2,658,406

VARIABLE SPEED FEED MECHANISM Filed May 4, 1951 2 Sheets-Sheet 2 /JTTOQNEYS Patented Nov. 10, 1953 VARIABLE SPEED FEED MECHANISM JohnGibson Mcllvain, Jr., East Caln Township, Chester County, Pa.

Application May 4, 1951, Serial No. 224,598

(Cl. f4-394) 9 Claims. 1

This invention relates to drive mechanisms,

especially intermittenty drive mechanisms, and

still more particularly to feed mechanisms for intermittently feeding aweb through a reciprocating press.

One object of the present invention is to generally improve intermittentdrive mechanisms. Afmore particular object is to improve mechanisms forintermittently feeding a web at high speed. In a copending applicationof Frederick Auer, Serial No. 678,612, filed June 22, 1946, now PatentNo. 2,548,136 and entitled Feed Mechanism, there is disclosedsuch amechanism intended to operate in synchronism with machines requiring -acontinuously moving web, a common example being the combination of aprinting machine with la cutting and scoring press. A slack loop isprovided between the machines and the web is kept under positive controlby feed wheels which are driven through a cam and roller mechanism whichcauses the wheels to be accelerated, then rotated -at uniform speed,then decelerated, and then dwell briefly for the cutting operation inthe press.

One object of the present invention is to generally improve theaforesaid accelerating feed mechanism. More speciiic objects are togreatly reduce the mass yof the parts which must be accelerated anddecelerated. Instead of a large heart-shaped cam it is only a smalldiameter gear which is subjected to the variable speed drive. A

large cam is still employed to introduce the accelerating anddecelerating components, but in accordance with the present improvementthis cam is a stationary cam which may be fixedly secured to the frameof the machine. Thus the cam may be made as heavy and strong -asdesired, instead of being minimized in mass, and so a sturdier drive isprovided. In accordance with other features and objects of theinvention, a number of accessory parts previously required areeliminated, and those parts which are employed remain continuously inmesh, thus affording posi- -tive control at all times.

It has been suggested to employ -a planetary drive in whichthe planetgears :are carried by `a spider-which is oscillated-by'linkage driven bya cam. A further object of the present invention is to simplify andimprove such an arrangement. More speciccbjects `are to eliminate thering gear; to `eliminate the need for the oifset cam with 'its special`drive means for rota-ting the same; to eliminate. the .spider andmultiple planet gears; and to devise a more compact and simple mechanismproviding a more directdrive.

The intermittentfeed wheels may be located at the entrant end of thepress, and the web may be drawn by slip Wheels at the discharge end ofthe press. However, in the -case of webs which are largely scored andcut away this may tend to tear the weband in accordance with a furtherVfeature of the invention both ends of the press are provided withintermittently operated feed wheels which exercise positive control `onthe web. That, however, requires identical movement of thefeed wheels atboth ends, and ithas been found that even a slight difference inbacklash or lost motion in gearing or chain drives as, for example, ifthe feed wheels at one end are driven from the feed wheels atthe otherend, is sufficient to tearthe web. The same is true if two supposedlyidentical accelerating cam mechanisms are provided at the ends of thepress.

Afurther objectof the present invention is to help insureidenticalrotation of the feed wheels, and with that object in view a symmetricaldrive is provided, a` single accelerating mechanism being connected tothe feed wheels at both ends of the press by gear trains made up ofequal numbers of gears of like type and dimension in order thatth'erollers may be subjected to the same probable lost motion or backlash.

To` accomplish the foregoing general objects, and such vother objects asmay hereinafter appear, my invention resides in the accelerating feedelements and their relation one to another 'as are hereinafter moreparticularly described in the following specification. The specificationis accompanied by drawings in which:

Fig. l is a small view schematically showing "a commonuse for theinvention;

Fig. 2 is a side elevation of a press with feed mechanism embodyingfeatures of the invention;

Fig. 3 is an end view of the accelerating feed mechanism employedin thepress of Fig. 2;

Fig. 4 is a partially sectioned plan view of the same; and

Fig. 5 i-s a partially section front elevation taken approximately inthe plane of the line 5-5 `of Fig. 4.

Referring to the drawing-and more particularly to Fig. l, the apparatuscomprises a-rst ma- -chine A which operates on a continuously movingwebB, and a second machine C which operates on the same web, with the webmoved only intermittently, there being -a slack loop of web D `cetweenthe two machines. The motor E runs continuously, and drives the machinesA and C, the machine C including accelerating feed mechanism to move theweb intermittently.

In the present case the machine A is a print, ing press, it beingunderstood that there may be a bank of printing presses formulti-colored printing, instead of a single press as shown, and themachine C is a punch press which may be used for scoring or cutting theweb. A typical problem may be to make blanks for milk containers, inwhich case the web is scored to mark the fold lines and is cut to markthe outlines of the blank.

Referring now to Fig. 2 of the drawing, the punch press C receives theweb B as fed to it intermittently by top and bottom feed wheels I2 andI4, these being intermittently driven by speed-up mechanism generallydesignated S. To maintain registration and to guard against cumulativechange in the size of the slack loop of web, compensating mechanism maybe provided. Such mechanisms are described in greater detail in thecopending application of Frederick Auer, Serial No. 678,612, now PatentNo. 2,548,136 previously referred to, and the compensation may takeeffect either by supplying a corrective movement through differentialgearing or, in the alternative, by means of a positive innite variabledrive indicated at V in Fig. 1, this being disposed in the driveconnection between the machines C and A.

The accelerating or speed-up mechanism S is shown-in greater detail inFigs. 3, 4 and 5 of the drawing, referring to which it will be seen thatthere is a rotatable input member 20 and a rotatable output member 22disposed coaxial therewith. A sun gear 24, preferably of small diameter,is disposed on one of Said members, in this case the output member 22,While a planet gear sector 26 is carried by the other member, in thiscase Vthe input member 20. The planet gear sector 26 meshes with the sungear 24 and is held against free rotation by means of an arm 28 fixed tothe sector. This arm extends outwardly from the sector and may be usedto oscillate the same relative to the input member 20.

For this purpose the arm 28 carries a cam follower 30 which is receivedin a stationary cam track 32, the said cam track extending around theaxis of the rotatable members 26 and 22. The cam track 32 is so shapedas to oscillate the sector 26 during each revolution of the same aboutthe axis of the members 20, 22, and this introduces accelerating anddecelerating components into the drive from the member 26 to the member22. In the specific case here illustrated the rotation of the outputmember 22 may be divided into four periods corresponding to rotation ofthe input member 20 as follows: acceleration for 108, uniform highvelocity for 54, deceleration lfor 108, and dwell for 90. These valuesare given solely by way of example and are not intended to be inlimitation of the invention, for it is evident that one importantadvantage of the present improvement is that it makes possible greatflexibility in the timing cycle which may be provided.

Considering the arrangement in greater detail, in the specic arrangementhere shown the input member 20 is a gear of relatively large diameter,the diameter being sufficient to make it possible to pivotally mount thegear sector 26 directly on the member 20, as indicated at 34, and forthis purpose the gear may be provided with a boss 36 to increase thebearing surface. The output member 22 is a shaft, and the gear 20 isfreely rotatable around the shaft 22, as is indicated in Fig. 3 by theball bearing 38. The sun gear 24 is fixedly secured to the shaft 22, asby means of a key 40. The mechanism is mounted on the side frame 42 ofthe machine in such a manner that the relatively large cam 32 may besecured directly against the frame, as is clearly shown in the drawing.In Fig. 3 it will be seen that the sun gear 24 is preferably disposedbetween the cam 32 and the input gear 20, in which case the arm 28 maybe mounted on a pivot projecting in one direction to the gear 20, whilethe cam roller 30 projects in the opposite direction. This arrangementhas the advantage that the radius of the cam track may become less thanthe radius of the gear 20, as shown near the bottom of Fig. 5.

A most important 4feature of the present invention is that it readilyprovides a dwell period. Fig. 5 shows the cam roller 30 in the dwellportion of the cam (which in the present case is long). The dwell isobtained by a part of the cam which may be developed by tracing themotion of the cam roller when holding the sun gear 24 stationary whilerolling the planet gear about the sun gear.

The present cam is laid out to accelerate the web for one-third thelength of a single sheet portion of the web, to feed the web at uniformhigh speed for one-third the length of the sheet, to decelerate the webfor one-third the length of the sheet, and to dwell for a timeequivalent to one-third of the total travel time of the web. In degrees,there is acceleration for 108, uniform velocity for 54, deceleration for108, and dwell for 90. The acceleration for 108 provides the same amountof sheet travel as the uniform high velocity provides in one-half thattime or 54.

One might provide a more gradual acceleration and deceleration byeliminating the uniform velocity part of the cycle. Thus one might haveacceleration, deceleration, and dwell alone. However, to obtain thedesired web travel or sheet length in the same limited time, such anarrangement would require a very high maximum velocity at the top speedbetween acceleration and deceleration. It is primarily with a view tolimiting the necessary maximum web speed that a period of uniformvelocity travel is employed between the acceleration and thedeceleration. However, the portion of the cycle used for uniformvelocity cannot be lengthened too much because the more it is prolongedthe sharper becomes the necessary acceleration and deceleration, whichagain is bad. Thus the cycle here employed is a compromise between adesire, on the one hand, to limit the maximum sheet velocity, and adesire, on the other hand, to provide a gradual acceleration anddeceleration.

In some cases it may prove desirable to have a somewhat more gradualacceleration and deceleration, and a somewhat higher uniform velocity tocompensate, but that still would retain the idea of a compromise motion,as explained.

In the present mechanism the diameter of the Aplanet gear is twice thatof the sun gear. This is done because there is a practical limit to theswing of the cam follower lever. In theory it might be carried to 180,but in practice should not be carried beyond, say and in the presentcase is much less than that, about '70".

The press is preferably provided with supply feed wheels at one end, anddischarge feed wheels at the other end, and they are preferably drivenfrom the accelerating mechanism by gear trains made up of equal numbersof gears of like type and dimension, in order that the supply lthemachine asser/roe .and discharge wheels maybe operatedalikeand :besubjected to-thesamefprobable llost motionor backlash. Thus 1in Figs. .4Land15 it ,will ;beseen gears 58 and 60. Thesefin turn vdrivespindles.6.2

and 64 (Fig. 4) whichcarry spur gears Staand-53. Referring now to flig.2 of .thedrawina .theg-spur turnmesh with gears -lll'and `lit-.whichturn ,feed wheels of vcorresponding diameter. `These,gea-rs also meshwith gears 1,8 and;80 which turn'. upper feed Wheels of correspondingdiameter. It Will thus be seen that the gear 44:trains are made as muchalike as .possible with a view to `insuring equal Vand `simultaneousfeed movement fat #both endsioi the press, andthus avoid stress orY.tearing of thevweb even though-*the web is ,weakened by removal oflarge portions by :the punching action of the press itself.

The punch press'Cshotvndn Figs. 1 and2 Vmay be of conventionalconstruction, it comprising a bolster or platen r82 reciprocated byfourvcorner rods 84 connected Vto links 86 operated byfeccentricsdrivenby gears 90. These meshwith gears'92 carried o n ashaft .9.4Which'also carries pulley B8 whichgreceives `belt it!! .leading :to .themain drive motor E previously referredito. `'One of the gears `il?,oranothergear,carriedrby the shaftgll, mesheswith the intermediateigear96, which in turn ,meshes with Y the rlarge input v.gear 20 previouslylreferred to, as is also lshown in Figs. 3 and 5.

To drive the printing press, `power -is taken from the shaftt94, andthrough bevelfgearingfof conventional character (notfshown) is led.tothe chain drive H12 shown in Fig. 1, which -runsto the main shaft 04oftheline vof printingpresses. The positive infinitely variable drive Vis interposed when such a drive ,isfdesired foricompensation, aspreviously mentioned It is believed that theconstructionv and operationof 'my improved `accelerating feed 4mechanism, as well as theadvantagesthereof, .will'be apparent vfrom the-foregoing;detailedidescription. The feed wheelsgrip theweb tightlyat .all;times, andmaintain positivefcontrol oftheiveb. 'This istrue at bothl endsofthe-press, and the-.webmay be acceleratedmoved.at Yhighspeed,;decelerated, and then causedto dwell,all inialmanner whichutilizes the available time most efficiently. vThe supplyand dischargewheels 4fareoperated alike, and are subjected to the same ,probable lostmotionor-backlash. Aseto the accelerating cam mechanism itse1fthe massof the. sun gear which must be accelerated and I'deceleratedis'vminimiZed. The oscillating gear sectortooisoffcom- -parativelysmallmass, and its movement is over only a comparatively small angle. The.large cam, Whichis the partof greatest massis absolutely stationaryitbeing boltedtothe-frame. of The input gear 2B whichcarries the gearsector is a fullcircular gearrotated at uniform speed, and `anyunbalance introduced by adding the gear sector is Vreadilycounterbalanced by the addition of an equivalent weight at Athe oppositeside. This ispreferalblydone, although not so shown inthe drawing inorder not to unduly complicate the same.

The present mechanism has the `advallltiee that there -is-nc jamming vorlockingpoint. It can even be turned in reverse direction without jammingor locking. Ithas the ,advantagesV of vrrovidir..ig-,unifolfrrl .01.harmonic acceleration and deceleration lif desired, and of providing yareal .-dwell, and fthe ,length 0f dwell may be made whatever is neededor desired. It has-theladvan- `tage that fthepartsare simple and open sothat they ,can-be beefed up asmuch as necessary,

and thus 4,can be subjected to heavy loads.

For example, in the disclosed mechanism two sets of feed rollers aredriven from a single cam mechanism, Aand if fdesired, Athree sets ormore `could b e so driven. Incidentally, when using two sets, `as `inFig. 5, it -is not necessary that the shafts pointdiametrically oppositeone another, nor `that the shafts be of equal length.

The ability-to beef up the mechanism leads ultimately to a higher speeddrive. This is so because the dwell period isusually lfixed by the.needs of the particular mechanism requiring the dwell, `in this casethepunch press.

To increase the overall speed the only thing that can be done is tospeed up the motion part of the cycle, and that increases the load onthe accelerating mechanism.

It willbe understood that while -I have shown a gear sector for theplanet, a fullgear might be employed; and conversely, while I haveVshown la vfull gear for the sun gear, a sector might be employed,particularly so when `using a lower gear ratio, say 1:1, .instead of theratioof 2:1

.here shown. n general it willproveless expensive and more satisfactoryyto employ the full sun gear even though only a `portion of theperipheryis used.

VConfipared to someprior mechanisms, it is not necessary to employalargering gear, nor to employ multiple planetgears `with a spider,norto employ a ,separate rotatable cam with special drive mechanism forrotating the same. lThe new .drive is simple, requires a minimum numberof parts, and is Kdirect, in nature. The new drive is compact indimension, `for the input and output members have acommonaxis, yet maybe dispcsedclosetooneanother in axial direction, for

Vinessence the axial dimension may be reduced to-.mlelythe sumof thethickness of the cam,

the sungear, and the input gear.

It will beiunderstood thattheinvention is not limited to Webfeedmechanism, and may be applied ,to-sheet feed mechanism, and indeed mayvbe applied to vother and wholly different mechanisms Whereanintermittent motion is Wanted, For example, `in automatic rmachinesemploying a turretthe lturret often is turned by a Geneva gearmechanism.Such mechanisms have proved troublesome because of their abruptacceleration, and theirshort travel time in. contrast withthe vvlongdwell time, which frequently'isfar greater than wanted. The presentmechanism `may be employed todrive a turret by simply introducing agearreductionbetween thevsun gear shaft and ,the turret shaft, with areduction. ratiocorrespending to the number of stations.

Thus the motionfromone station t0 the next isprovided bythe presentmechanism, and may be apportioned. as desired `to providegradualacceleration Vand,decelerationand a limited dwell .period no greatervthan needed for the operation to be per- ,formed fat the station.Thismakes the full re- Hxnaining f timev available Yfora rmore, gradualand .therefore more satisfactory acceleration and deceleration.

It vwill be understood that While I have shown and describedmyvinvention ina preferredl form, changes, may beA made in the structuredisclosed, withoutdeparting from ,the ,scope ofthe invention, as soughtt be defined in the following claims. In the claims the reference to asun gear is not intended to exclude the use of a sun gear sector, andthe reference to a planet gear sector is not intended to exclude the useof a full planet gear. The quoted terminology is employed simply foreasier recognition and consequent clarity.

I claim:

1. An accelerating feed mechanism comprising a rotatable input member, arotatable output member coaxial therewith, a sun gear on one of saidmembers, a planet gear sector carried by the other member and meshingwith the sun gear, an arm extending from said gear sector foroscillating the same, a cam follower carried by said arm, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being so shaped as tooscillate the sector during revolution of the same and to therebyintroduce accelerating and decelerating components into the drive fromone of said members to the other.

2. An accelerating feed mechanism comprising a rotatable input member, arotatable output member coaxial therewith, a sun gear on the outputmember, a planet gear sector carried by the input member and meshingwith the sun gear, an arm extending outwardly from said gear sector foroscillating the same, a cam follower carried by said arm, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being so shaped as tooscillate the sector during revolution of the same and to therebyintroduce accelerating and decelerating components into the drive fromsaid input member to said output member.

3. An accelerating feed mechanism comprising a frame, a rotatable inputmember, a rotatable output member coaxial therewith, a sun gear on theoutput member, a planet gear sector carried by the input member andmeshing with the sun gear, an arm iixedly related to and extendingoutwardly from said gear sector for oscillating the same, a cam followercarried by said arm on the side remote from the input member, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being xedly secured tosaid frame and so shaped as to oscillate the sector during i'evolutionof the same and to thereby introduce accelerating and deceleratingcomponents into the drive from said input member to said output member,said sun gear being disposed between said cam and said input member, andsaid cam being disposed between said sun gear and said frame.

4. An accelerating feed mechanism comprising a frame, a rotatable inputmember, a rotatable output member coaxial therewith a sun gear ontheoutput member, a planet gear sector carried by the input member andmeshing with the sun gear, an arm fixedly related to and extendingoutwardly from said gear sector for oscillating the same, a cam followercarried by said arm on the side remote from the input member, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being xedly secured tosaid frame and being so shaped as to oscillate the sector duringrevolution of the same and to thereby introduce accelerating anddecelerating components into the drive from said input member to saidoutput member, said sun gear being disposed between said cam and saidinput member, and said cam being disposed between said sun gear and saidframe, and said sun gear, said gear sector, and said lever all beingdisposed in a common plane perpendicular to the axis of the mechanism.

5. An accelerating feed mechanism comprising a frame, a rotatable inputmember, a rotatable output member coaxial therewith, a sun gear on theoutput member, a planet gear sector carried by the input member andmeshing with the sun gear, an arm nxedly related to and extendingoutwardly from said gear sector for oscillating the same, a cam followercarried by said arm on the side remote from the input member, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being ixedly secured tosaid frame and being so shaped as to oscillate the sector duringrevolution of the same and to thereby introduce accelerating anddecelerating components into the drive from said input member to saidoutput member, said sun gear being disposed between said cam and saidinput member, and said cam being disposed between said sun gear and saidframe, an output shaft carrying said sun gear, said shaft passingthrough said input member, and anti-friction bearings between said inputmember and said output shaft.

6. A drive mechanism comprising a rotatable input member, a rotatableoutput member coaxial therewith, a sun gear on the output member, aplanet gear sector carried by the input member and meshing with the sungear, an arm fixedly related to and extending outwardly from said gearsector for oscillating the same, a cam follower carried by said arm, anda stationary cam track receiving said cam follower and surrounding theaxis of said rotatable memu bers, said cam track being so shape-d as tooscillate the sector during revolution of the same and to therebyconvert uniform rotation to nonuniform rotation, a part of said camtrack being shaped to eliminate forward motion of the sun gear over aperiod.

7. A drive mechanism comprising a rotatable input member, a rotatableoutput member coaxial therewith, a sun gear on the output member, aplanet gear sector carried by the input member and meshing with the sungear, an arm fixedly related to and extending outwardly from said gearsector for oscillating the same, a cam follower carried by said arm, anda stationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said cam track being so shaped as tooscillate the sector during revolution of the same and to therebyconvert uniform rotation to non-uniform rotation, a part of said camtrack being developed to correspond to the motion of the cam followerwhen the planet gear sector is rolled about the sun gear while holdingthe sun gear stationary, thereby providing a dwell period.

8. An accelerating feed mechanism comprising a frame, a rotatable inputmember, a rotatable output member coaxial therewith, a sun gear on theoutput member, a planet gear sector car ried by the input member andmeshing with the sun gear, an arm fixedly related to and extendingoutwardly from said gear sector for oscillating the same, a cam followercarried by said arm on the side remote from the input mmber and aStationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said sun gear being disposed betweensaid cam track and said input member, and said cam track being disposedbetween said sun gear and said frame, said cam track being xedly securedto said frame and being so shaped as to oscillate the sector duringrevolution of the same and to thereby convert uniform rotation tonon-uniform rotation, a part of said cam track being shaped to eliminateforward motion of the sun gear ovei` a period of time.

9. An accelerating feed mechanism comprising a frame, a rotatable inputmember, a rotatable output member coaxial therewith, a sun gear on theoutput member, a planet gear sector carried by the input member andmeshing with the sun gear, an arm xedly related to and extendingoutwardly from said gear sector for oscillating the same, a cam followercarried by said`arm on the side remote from the input member, and astationary cam track receiving said cam follower and surrounding theaxis of said rotatable members, said sun gear being disposed betweensaid 'iii cam track and said input member, and said cam track beingdisposed between said sun gear and said frame, said cam track beingxedly secured to said frame and being so shaped as to cscillate thesector during revolution of the same and to thereby convert uniformrotation to nonuniform rotation, a part of said cam track beingdeveloped to correspond to the motion of the cam follower When theplanet gear sector is rolled about the sun gear while holding the sungear stationary, thereby providing a dwell period.

JOHN GIBSON MCILVAIN, JUNIOR.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,080,978 Johnston Dec. 9, 1913 2,253,367 Di Prima Aug. 19,1941 2,309,595 James Jan. 26, 1943 2,498,036 Grace Feb. 21, 19502,536,754 Dudley et al Jan. 2, 1951

